DEET is the standard in mosquito repellants. It is both effective and safe, as reported in DEET – Is It Safe? But what are the alternatives? Do natural extracts work as well as DEET? Are there safer man-made products? Are there better natural products? In this blog post I will review the current options that are worth considering.
If you are looking to fend off the Zika virus, check this out: Mosquito Repellents That Work Against Zika
Mosquito Repellents – What Makes a Good?
We already have a product that is both effective and safe – DEET. For a new product to be considered better than the standard it must either be more effective than DEET or it must be safer. If you are worried about diseases like West Nile, then it needs to be at least as effective as DEET – why would you take a chance on a less effective product?
Picaridin (Icaridin)
Picaridin, also called Icaridin, has been sold in the US since 2005. It is as effective as DEET, and at the 20% concentration level it might last slightly longer than 30% DEET. It does not have an odor, and does not dissolve plastic. Unlike DEET it does not irritate skin and eyes. It does not have any known health risks, but testing is not as extensive as for DEET. It is recommended by the World Health Organization.
IR3535
IR3535 has been in use in Europe for over 20 years, but was not registered in the US until 1999. It can irritate eyes, it dissolves some plastics, but it has no other health risks. At the 20% level it is as effective as DEET. It is recommended by the World Health Organization.
Oil of Lemon Eucalyptus (PMD)
PMD is the name given to the active ingredient in oil of lemon Eucalyptus. At 26%, PMD is as effective as 30% DEET, but it only lasts for 4-6 hours, so it needs to be applied more frequently. At 10%, it is only effective for a couple of hours. The manufacturer does not recommend it when there is a high risk of West Nile. It should not be used on children under 3 years of age.
The synthetic version of PMD is less likely to cause a skin allergy than the natural version. PMD is NOT recommended by the World Health Organization.
Natural Oils
Citronella has been discussed in Citronella Plant Keeps Mosquitoes Away. A number of other natural oil products are available commercially, and can be made using home made recipes. The following oils have shown some promise: caster, citronella, cedar, clove, lemongrass, peppermint, rosemary and soybean.
All of these provide some protection, but none of them provide protection for more than a couple of hours – some for only 30 minutes. They need to be applied frequently.
People are drawn to these natural products, but many of them produce allergic reactions. The table below of known allergens was published by The Environmental Working Group (ref 1).
it is important to understand that these oils have not been tested for their health effects.
Natural does NOT mean safe.
While a number of commercial products exist that contain a mixture of natural oils, none of these have been approved by the agencies I looked at. If you care about remaining disease free, they are not your best choice.
Other Posts About Mosquitoes?
Mosquito Repelling Devices – Do They Work?
Mosquito Apps for Your Smart Phone – Do They Keep Mosquitoes Away?
Mosquitoes Repelled By Fragrant Plants
Mosquito Repellents That Work Against Zika Virus
References:
1) The Environmental Working Group – Guide to Bug Repellents: http://www.ewg.org/research/ewgs-guide-bug-repellents/repellent-chemicals#picaridin
2) EPA pesticide Fact Sheet for Picaridin: http://www.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-070705_01-May-05.pdf
3) EPA pesticide Fact Sheet for Oil of Lemon Eucalyptus: http://www.epa.gov/opp00001/chem_search/reg_actions/registration/fs_PC-011550_01-Apr-00.pdf
4) EPA pesticide Fact Sheet for IR3535: http://www.epa.gov/opp00001/chem_search/reg_actions/registration/fs_PC-113509_01-Jan-00.pdf
Photo Source: Hospital News Checker
DEET works for me but it’s mightily expensive. I grew a large swathe of Nepeta Cataria (catnip) to watch the fun when my neighbours cats visited my gardens. I did some reading on Google scholar and was surprised to see that the oil from the plants had been trialled as a repellent in Africa with some success. I don’t recall the name of the particular compound within the oil that was isolated as the likely candidate for the repellent quality, you will find it if you look.
Anyway I extracted oil using a small CO2 supercritical machine that I use for other projects 😉 and tried it on one side of my body. It works, the smell I am not keen on at all but it is effective.
If you want to try it for yourself you could probably get a decent extraction using a home built crude and simple steam distillation apparatus.
I still get bitten but not so often at all.
I find DEET to be relatively cheap. Buy as a liquid and only use a bit.
The extracted oil might work, but how harmful is it? Has it been tested for safety? The toxicity of many of these oil have not been properly tested.
Robert, I agree that DEET is probably safe and I use it when buggers are thick. However, if someone says try Avon Skin So Soft, just because there is no science, it doesn’t mean it doesn’t work. I have tried it and it works for me. However, it is not as good as DEET and who knows, the EPA has probably not even ruled on Skin So Soft because it is a body lotion, not sold as an insect repellent.
I like science, but sometimes there is no money to have the studies done, so we fall back to empirical evidence. It is works for some people, why not let them say so without shaming them?
This is a science based web site, and I don’t want people reading incorre3ct information and then leaving and spreading the myth.
If it works, then there is science to support it. If not, then we don’t know it works.
Okay Robert. I appreciate the boundaries. A scientific approach to understanding our world is very helpful. No question. And I really appreciate your perspective and website which attempts to put to rest the myths and mis-information. However, science has many definitions, depending on the perspective and agenda of the one using “science”. We’ve all been conditioned from early childhood to just “trust the science”, similar to trusting the priests of other eras. It would be helpful to hear your definition of science. It would help in understanding your boundaries.
Science are the accepted conclusions of the majority of scientists, which is supported by published research.
Thank you, Robert. Very helpful and I appreciate the devotion to rigorous scientific inquiry and conclusions. Without it, we are left to following myth and superstition. Your use of the word science in the plural (which I am still not sure is proper grammar) caused me to research the grammatical use of the word, is it plural or singular. That search lead me to a very interesting treatise on the “Grammar of Science” that I found very useful and may be useful to your readers as they sift through our body of knowledge to ascertain what is reliable knowledge and what is myth. https://homepages.abdn.ac.uk/nph120/meteo/Gramsci.pdf
Robert,
No mention of the old Avon “Skin So Soft”. My anectodal evidence was that it worked. It could be highly toxic, for all we know, but it smelled better and my wife liked it over the DEET bug spray. Any thoughts on that stuff?
It has limited value as a bug spray. https://www.gardenmyths.com/mosquito-repellents-best-options/
I’m looking for something to plant in the backyard for mosquito control. I read all the wonders of deet. But are there any practical measures I can take to make my space less desirable to the pests? I have very young grandkids that spend a lot of time with us.
Our neighbors have an in- ground pool that is not being used. They drained it. But now we’ve had heavy rains the last few weeks. I’m a little freaked out.
Thanks for any suggestions.
Remove all standing water to stop them breeding. Then remove all vegetation so they have no place to hide during the hot midday sun – including lawn grass. That keeps them away. Clearly the second point is not too practicable if you want a nice garden but it does work. There is nothing you can plant to keep mosquitoes away.
I plant Centollia every year works great never ate up by them we shake the plant get the scent out and sit outside by the pool no problems
Anecdotal evidence without proper controls is not worth very much.
https://www.gardenmyths.com/anecdotal-evidence-not-worth-the-screen-its-displayed-on/
After reading your posting, we tried (P)icaridin on a canoe trip through very buggy northern Quebec last week. The specific product was PiActive, the first Canadian product. It was launched by KUUS in May 2015 and is currently available at Mountain Equipment Co-op and a few other retailers. (P)icaridin is MUCH, MUCH more pleasant to use than DEET and is highly effective but washes off in just a sprinkle of rain or wading through water. Apparently (P)icaridin’s chemical formulation contains more oxygen than DEET which is the reason it is more water soluble. We encountered a horde of hungry biters at a portage just as the skies opened and rain pelted down. At that moment, DEET would definitely have given more protection. We will definitely continue to carry both (P)icaridin and DEET as a back-up in the future.
Very interesting. None of the references mentioned this – but then how many authors canoe? I had been an avid canoeist with several trips to the Arctic.
I wonder if sweat also removes (P)icaridin? One problem with DEET is that seat does tend to have it run in the eyes – not so much fun on a long portage.
One Internet source claimed that (P)icaridin does not sting the eyes, a claim not made in relation to PiActive. I did experience mild stinging, probably less than would have been caused by DEET, when sweat trickled down. We did not encounter sufficient heat and humidity to say whether heavy perspiration would diminish the effectiveness of (P)icaridin.
Great post. I tried a lemon grass mixture by a top brand, and it had the after-odor of poop! And it was not the compost or me! Also, when I am vegetarian and eat less fat (and no animal fats) I get far less bites. I think the pesky skeeters pass me by as just another cute tomato!
Thanks for the info. I finds your site very informative.
I am a mosquito magnet! They love me. Pretty much looks like I have the chicken pot all summer. So yes, I pretty much used to gargle with DEET. I’m probably going to drop dead any day now. I’ve done the whole lemon oil deal and that’s been pretty effective. I also like tea tree oil for keeping those pests away. And when hiking, I stuff dryer sheets anywhere and everywhere, especially in my socks and I find this highly effective!!!
I just don’t get it – If you are a mosquito magnet, why not just use a safe product that works – DEET?
Good Morning Robert,
Firstly, I regard much of your blogging highly but have to take issue with your perceived standpoint and advice on particular aspect; I love a level playing field so perhaps I will be allowed to restore a little balance here if I may?
C12H17NO, or DEET as it is more commonly know is used as both an insect repellent and as a pesticide.
DEET was first developed by the US Army back in 1946 for military personnel use and was registered on the open market for commercial use in 1957.
You will find that the United States Environmental Protection Agency (EPA) had concerns over the toxicology and possible adverse effects of DEET from back before the 80s and ongoing; as per this 1980 report:
http://nepis.epa.gov/Exe/ZyNET.exe/9100CQB8.txt?ZyActionD=ZyDocument&Client=EPA&Index=2011%20Thru%202015%7C1995%20Thru%201999%7C1981%20Thru%201985%7C2006%20Thru%202010%7C1991%20Thru%201994%7C1976%20Thru%201980%7C2000%20Thru%202005%7C1986%20Thru%201990%7CPrior%20to%201976%7CHardcopy%20Publications&Docs=&Query=deet&Time=&EndTime=&SearchMethod=2&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C76THRU80%5CTXT%5C00000014%5C9100CQB8.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=15&FuzzyDegree=0&ImageQuality=r85g16/r85g16/x150y150g16/i500&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1
The EPA have repeatedly highlighted significant concerns from exposure and dermal absorption through either frequent use of DEET and/or in particular using DEET formulas on children. As shown in this EPA report of 1998:
http://nepis.epa.gov/Exe/ZyNET.exe/200006H3.txt?ZyActionD=ZyDocument&Client=EPA&Index=2011%20Thru%202015%7C1995%20Thru%201999%7C1981%20Thru%201985%7C2006%20Thru%202010%7C1991%20Thru%201994%7C1976%20Thru%201980%7C2000%20Thru%202005%7C1986%20Thru%201990%7CPrior%20to%201976%7CHardcopy%20Publications&Docs=&Query=deet&Time=&EndTime=&SearchMethod=2&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C95THRU99%5CTXT%5C00000011%5C200006H3.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=15&FuzzyDegree=0&ImageQuality=r85g16/r85g16/x150y150g16/i500&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1
There are numerous reports available for and against the use of DEET; just a few here:
– http://www.environmentalhealth.ca/spring03hazards.html
– https://www.nlm.nih.gov/medlineplus/ency/article/002763.htm
– http://www.scientificamerican.com/article/is-it-true-that-the-deet/
– http://npic.orst.edu/factsheets/DEETgen.html
Moving on to a little about me and my point here.
I am a medical specialist (of 22 years’ experience working for Médecins Sans Frontières [MSF] throughout the world) and in my spare time, of which there has been precious little, a qualified Royal Horticultural Society [RHS] horticulturalist.
I have no argument with there being a sincere requirement for an effective mosquito/airborne insect repellent. I do question whether we should be advocating the use of DEET and DEET alone, as seems to be the case here; I would not, and will not, put a pesticide on my children. There are other extremely effective natural compositions readily available. I, and many of my colleagues, have used them for years.
With regard to natural oils, Where you state “….all of these provide some protection, but none of them provide protection for more than a couple of hours – some for only 30 minutes. They need to be applied frequently…”. Obviously, that is because the essential oils alone evaporate. However, this is NOT the case if they are used in the right combination and within the right carrier such as a beeswax or shea butter products; we have found that they are effective for up to eight hours in intense jungle environments.
My work environments have regularly required me to wear some form of insect deterrent on an almost daily basis, sometimes for weeks at a time, and I would never countenance wearing any DEET product for anywhere near that period, if at all.
The products I use are safer than and as effective as any DEET-based product.
I find it also rather disingenuous of you to also write that “….People are drawn to these natural products, but many of them produce allergic reactions….” whilst ignoring any harmful effects from DEET.
The anticipated response will next be, that there is no, or very limited, scientific proof to back this up; this is no more than anecdotal ‘evidence’.
To counter this let’s look at who produces the main market insect repellent products: OFF, Autan and Raid. No less than SC Johnson, the global manufacturer of household cleaning supplies and consumer chemicals with an annual sales figure in the region of $8 billion. Let’s not be naïve an consider for one moment that they have no sway or influence in advertising, politics, scientific study outcomes or squeezing out the ‘little man’.
So who is the ‘little man’; that should read ‘little men and women’ as the main producers of the DEET-free bug deterrents that don’t want toxic chemicals for their children and their circle of friends. In the main they do not have any way or influence in advertising, politics let alone the finance to exercise a scientific study.
I will not advertise any of these products myself that would not only be hypocritical and lead to claims of impartiality, but also defeat the point of my comments. A simple google search for bug repellents with a few of the characteristics I have outlined should suffice should you care to test for yourself; I get mine from the Virgin Islands.
In conclusion, I agree that the plants themselves have little deterrent, but their natural oils combined in well-developed and tested combinations certainly do.
I will continue to read your blog of course.
Best regards,
Nicolas.
Thanks for the great post and the references.
Lets look at the references. The first one, from 1980, by the EPA concludes that “criteria for unreasonable adverse effects have not been met”. They do recommend more studies – doesn’t everyone. So they did not find a problem with DEET, but maybe there is one.
The second reference, dated 1998, also from the EPA concludes that Deet has been “shown to be of low acute toxicity and normal use does not present health concerns. Because of use patterns, people are not exposed to residues of DEET through diet”. In 1998 the EPA seems confident that DEET is safe.
In a more recent study: “The EPA did a safety review of DEET in 2014 and concluded that “The Agency has not identified any risks of concern to human health, non-target species or the environment”” from https://www.gardenmyths.com/deet-is-it-safe/
I think the EPA is quite clear on their position and it has not changed in the last 35 years. DEET is safe.
The third reference is from the Environmental Health Association of Nova Scotia. They discuss concerns raised by Dr. Abou-Donia which I have already discussed in https://www.gardenmyths.com/deet-is-it-safe/ . Their statement about his work is incorrect and this is what Dr. Abou-Donia has to say about the safety of DEET “If used sparingly, infrequently and by itself, DEET may not have negative effects – the literature here isn’t clear, But frequent and heavy use of DEET, especially in combination with other chemicals or medications, could cause brain deficits in vulnerable populations.”
They also go on to say that planting certain plants like citronela in the garden will ward off mosquitoes, when science has clearly shown this is not correct. This reference is not creditable.
The next reference by Medline Plus discusses “harmful effects from breathing in or swallowing bug spray”. As your reference from the EPA says people are not likely to ingest DEET. So this is not really an issue, except in rare cases.
The next reference from Scientific American makes the same mistake as the EHANS. discussed above, regarding Dr. Abou-Donia. It is clearly not a credible report.
Your last reference from the National Pesticide Information Center indicates no health issues with DEET. I am not sure why you included it to make your case. They say DEET does not cause cancer, and exposure of pregnant mothers had no effect on the new borns.
If you need protection daily for long periods of time, I understand your concern with DEET. The danger of chemicals is based on their properties, how they react in the body, and most important the dose. Lots of people drink coffee with no ill effects even though it is full of carcinogens. The dose is so low they are not a concern.
The claim that big business is influencing EPA reports and political decisions is one you see a lot when someone can’t prove their position on a scientific basis. Sure it can happen – but with no real proof it is not a very convincing argument.
You say you use a natural oil product which has beeswax or shea butter to make it “as effective as DEET”, but you need to get it from the Virgin Islands? If it was that good and safe it would be available everywhere. Where is the reference showing that this product works?
I did a Google search for “insect repellent with natural oils and beeswax” and it did not show up on the first page.
Try Avon skin so soft
Why? The science does not support its use if you want a product that works.